1. Field of the Invention
The present invention relates to an improved dark slide locking system for a photographic film holder, which is adapted to prevent a dark slide from undesired sliding out when it is in an inserted state.
2. Description of the Prior Art
In conventional locking systems of this type, a rotatable stopper which has its upper end bent is mounted on the body of a film holder near a dark slide inserting opening thereof to lock the upper end of a dark slide by the bent portion of the stopper. However, the conventional locking systems are accompanied by disadvantages. Because the stopper is freely rotatable, it may rotate during the handling of the film holder, for example, in attaching the film holder and putting it in a box, so that the stopper may disengage from the end edge of the dark slide, allowing the dark slide to slide out. In this manner, the conventional locking system has no reliability.